Radio antenna for automobiles



June 17, 1941;

G. MOUNTJOY RADIO ANTENNA FOR AUTOMOBILES Filed Sept. 29, 1939 RECEIVER7'0 RECEIVER INVENTOR. GARRAR%UN 7:10)

' ATTORNEY.

r0 RECEIVER Patented June 17, 1941 RADEO ANTENNA FOR AUTOMOBILES GarrardMountjoy, Manhasset, N. Y., assignor to Radio orporation of America, acorporation of Delaware Application September 29, 1939, Serial No.297,676

l illaims, (61. 259-33 7 This invention relates to a novel antenna andits installation on automobiles or other vehicles. There are in use atthe present time many types of antennae adapted for installation onvehicles, such as, the rod or mast type which 1 may either be supportedfrom the cowl of the vehicle or mounted on the rear bumper; the kindthat extends rearwardly and above the roof or top of the car; and thetype that is mounted underneath the running board or car chassis. Thelatter or undercar type has been found inefficient and insensitive dueto its low effective height above ground, the shielding efiect by theautomobile body, and the static electrical disturbances caused by thetires of the car while in motion. The other mentioned types while theyare fairly efiicient electrically are objectionable to many users ofautomobile radios because they are conspicuous and detractfrom the.appearance of the automobile.

It is therefore one of the main objects of my invention to provide asimple and efficient antenna structure adapted to be readily mounted onthe top or roof of the car, and which is capable of adjustment in amanner such that during silent periods of the radio the antenna conformsto the contour of the car top and lies flush thereon, 'while duringperiods of radio reception the antenna is caused to be elevated to asuitable height above the car top.

Another object of the invention is to provide an antenna which isornamental and will add to the appearance of the car. This isaccomplished by embedding the antenna wire or conductor within a rod orsheath of moldable substance, which may be of any desired finish orcolor to harmonize with the car.

The novel features characteristic of my invention are set forth withparticularity in the appended claims. The invention itsel'i, however,both as to its construction and the mode of operation together withother objects and advantages thereof, will best be understood byreference to the following description taken in connection with theaccompanying drawing in which 1 Fig. 1 is a side elevational viewshowing the antenna structure according to my invention and its mountingon the car top,

Fig. 2 is an enlarged cross-sectional view of the antenna structure perso taken along the line Z2 of Fi 1,

Fig. 3 is a front view of the means employed to raise and lower theforward end of the antenna,

Fig. 4 is a view similar to Fig. 2, but showing a modification wherein agroove is formed lengthwise in the top of the car for accommodating theantenna in its lowered position,

Fig. 5 is a View similar to Fig. 1 and showing a modified form of theinvention, and

Fig. 6 is a detail showing the manner of adjusting the antenna structureof Fig. 5.

Corresponding and like parts are referred to in the followingdescription and designated in the several figures of the drawing by likereference characters.

Referring now to Fig. 1, the antenna is indicated generally by referenceI and extends lengthwise along the top of the car. In its inoperativeposition or during silent periods of the receiver the antenna is causedto conform to the contour of the car top 2 so that the same is hardlyconspicuous. The antenna is comprised of a central conductor 3 which maybe of copper or other suitable conducting material and a sheath ofinsulating material 4, preferably of moldable, slightly flexiblematerial, such as Celluloid or Cellophane, which surrounds the centralconductor. Preferably, the central conductor is not extended to the fulllength of the insulating rod, it being suiiicient if it terminates at areasonable distance from the anchored portion of the antenna, otherwisethere would be a shunting effect of the induced signal voltage byunwanted capacitance between the antenna and the counterpoise or groundportions of the signal pick-up system.

One end of the antenna structure is suitably clamped or otherwiseattached to the movable portion of a hinge 5 located towards the rear ofthe car top, the fixed portion of the hinge being attached to the top byscrew means. Actually the hinge 5 may be omitted if the insulatingmaterial is sufficiently flexible. In that case the point of attachmentmay be rigid and permanent. The forward end of the antenna structure islead through an opening in the forward end of the car top fitted withsuitable means such as a 'watertight bushing l. A pair of, frictionrollers 8 and 9 are adapted to receive between them and guide theforward end of the antenna structure, and a crank arm It! withinconvenient reach of the operator is associated with one of th frictionwheels, such as 9, whereby the forward end of the antenna structure maybe raised or lowered for the purpose heretofore explained the positionof the antenna in the raised position being shown in dotted lines inFig. 1. A flexible leadin conductor H is connected between the forwardend of the antenna and the radio receiving set I2 which may be mountedbehind the dashboard, on the fire-wall or any other suitable location asknownin the prior art.

If preferred the top of the car may be provided with a longitudinallyextending groove or trough l3 of suitable depth to accommodate partly orentirely the antenna structure, as shown in Fig. 4, so that during idleor non-reception periods it will be less likely for the antenna to beconspicuous, especially when the insulating material is given the samecolor as the finish of the car. If desired the insulating material maybe colored differently than the car to provide a pleasing contrast, andthereby enhance the appearance of the car.

In Fig. 5 I have disclosed a further modification of my invention. Inthis case the opening in the car top for leading-in the forward end ofthe antenna structure is dispensed with, and I have shown the use of anantenna rod l which is entirely of conducting material, such as steel,cooper or brass, and which has some degree of flexibility in order toconform to the contour of the car top. It will be understood of coursethat the antenna structure 2 of Fig. 1 may also be used in place of I inthis modification. According to Fig. 5 the vertical bar I 4 which isusually provided between the two front windows of present day cars isprovided with a longitudinal bore l9 and an insulating sleeve 29 throughwhich the forward portion of the antenna extends. The bar 14 is furtherprovided on its back side with a slit [5 through which a manual memberl6 fastened to the antenna extends inwardly within convenient reach ofthe and I therefore do not wish that my invention be limited to theprecise embodiments which have been illustrated by way of example. Ionly intend to limit my invention as required by the prior art andappended claims.

What I claim as my invention is:

1. An antenna for installation on the tops of motor vehicles, comprisinga rod of insulating material and a conductor embedded therein, said rodbeing attached at one end to the top of the vehicle, the opposite end ofthe rod extending through the top, and means within the vehiclecooperating with the latter end whereby the same may be raised orlowered at will.

2. An antenna for installation on the tops of motor vehicles, comprisinga rod of conducting material, said rod being attached at one end to thetop of the vehicle, the opposite end of the rod extending through thetop, and means within the vehicle cooperating with the latter endwhereby the same may be raised or lowered at will.

3. An antenna for installation on the tops of motor vehicles, comprisinga rod of moldable insulating material and a conductor embedded thereincapable of conforming to the contour of the vehicle top, means forpivotally mounting one end of said rod on the vehicle top toward therear end thereof, the vehicle top having at its forward end an aperturethrough which the other end of said rod is adapted to extend and meanscooperating with said other end of the rod for elevating the same abovethe vehicle top into an operative position.

4. An antenna for installation on the tops of motor vehicles, comprisinga rod of conducting material capable of conforming to the contour of thevehicle top, means for pivotally mounting one end of said rod on thevehicle top toward the rear end thereof, the vehicle top having at itsforward end an aperture through which the other end of said rod isadapted to extend; and means cooperating with said other end of the rodfor elevating the same above the vehicle top into an operative position.

GARRARD MOUNTJOY.

